The present invention relates to improvements in sealed universal pivot joints for push-pull cable terminal assemblies and is herein illustratively described by reference to the presently preferred embodiments thereof. However, it will be recognized that certain modifications and changes therein with respect to details may be made without departing from the essential features involved.
Flexible push-pull coaxial cables used in a wide variety of remote control applications comprise flexible inner and outer coaxial cable members with suitable terminal fittings on the ends of the respective members. At one or both ends of the cable assembly, the projecting end of the inner cable member carries a rod-like extension fitting that serves as a load coupler that, together with the connected immediately adjoining portion of the center cable, requires both support and guidance, as well as a means to effect a seal around the same and around the cable so that dirt and moisture cannot enter the cable assembly. Such a guiding support and seal means capable of functioning as a universal joint in order to accommodate the variously deflected positions which the load coupler rod may have to assume under operating conditions, must satisfy certain practical requirements as well as the functional ones mentioned. To be commercially practicable, the device must be relatively inexpensive to manufacture, easily assembled, sturdy and durable. In many applications, the cable assembly operates to perform cyclic control functions literally thousands of times within an operating lifespan. Oftentimes, load forces and moment couples reacting on the cable members and fitting assemblies are severe and are imposed during each operating cycle and with the end fittings laterally deflected out of coaxial alignment with the anchored terminal fitting of the outer cable member. It is therefore important to permit the inner cable member and its extension rod fitting to flex as required and yet to protectively limit the degree of flexure so as to minimize fatigue failures as well as maintain the integrity of the cable assembly seals.
A broad object of this invention is to provide an improved guiding support and seal means for coaxial cable assemblies solving the foregoing problems in an economic and practicable manner suitable for commercial use. More specifically, it is an object hereof to provide a readily manufactured and assembled device, and a sturdy and durable wear-resistant device of the nature indicated.
A further object of this invention is to provide such a device, the parts of which are few and simple and may be manufactured as relatively low cost with the necessary degree of dimensional precision so as to provide an effective durable seal without complicating the steps required to assemble the mechanism.